Overview
The TUSB2077A, produced by Texas Instruments, is a 3.3-V CMOS device designed as a 7-port USB hub compliant with the USB 2.0 specification. This device operates without the need for software programming, as it is implemented with a digital state machine rather than a microcontroller. It integrates fully compliant USB transceivers for all upstream and downstream ports, supporting both full-speed and low-speed devices by automatically adjusting the slew rate based on the attached device's speed.
The hub supports two power source modes: self-powered mode, which can support up to seven downstream ports, and bus-powered mode, which supports up to four downstream ports. It also features power switching and overcurrent reporting, either on a per-port or ganged basis, and supports suspend and resume operations.
Key Specifications
| Parameter | Value |
|---|---|
| Package | 48-Pin LQFP (PT) |
| Operating Temperature Range | 0 to 70°C |
| Power Source Modes | Self-Powered (7 ports), Bus-Powered (4 ports) |
| Downstream Ports | Up to 7 ports, full-speed and low-speed support |
| Power Management | Individual-port or ganged-port power management |
| Clock Operation | 6-MHz or 48-MHz clock input |
| Junction Temperature | Up to 115°C (simulated), 150°C (absolute maximum) |
| Thermal Resistance | Junction-to-ambient: 66.2°C/W, Junction-to-case (top): 21.1°C/W |
Key Features
- Fully compliant with the USB 2.0 specification as a full-speed hub
- Integrated USB transceivers for all upstream and downstream ports
- 3.3-V low-power ASIC logic
- Two power source modes: self-powered and bus-powered
- Power switching and overcurrent reporting on a per-port or ganged basis
- Supports suspend and resume operations with a suspend status pin available for external logic power down
- Custom vendor ID and product ID support with external serial EEPROM
- 3-state EEPROM interface allows EEPROM sharing
- Push-pull outputs for PWRON eliminate the need for external pullup resistors
- Noise filtering on OVRCUR provides immunity to voltage spikes
- Three LED indicator control outputs for visualized monitoring of hub and port status
- No special driver requirements; works seamlessly with any operating system with USB stack support
Applications
- Computer systems
- Docking stations
- Peripheral devices such as printers, scanners, and keyboards
- USB hubs in various consumer and industrial products
Q & A
- What is the TUSB2077A and what are its primary functions?
The TUSB2077A is a 7-port USB hub that complies with the USB 2.0 specification. It provides up to seven downstream ports and supports both full-speed and low-speed devices.
- What are the power source modes supported by the TUSB2077A?
The TUSB2077A supports two power source modes: self-powered mode, which can support up to seven downstream ports, and bus-powered mode, which supports up to four downstream ports.
- How does the TUSB2077A manage power to its downstream ports?
The TUSB2077A can manage power on a per-port or ganged basis. In individual-port management, power is switched on or off for each port individually. In ganged mode, power is switched on or off for all ports simultaneously.
- What clock frequencies does the TUSB2077A support?
The TUSB2077A supports both 6-MHz and 48-MHz clock frequencies.
- Does the TUSB2077A require any software programming?
No, the TUSB2077A does not require software programming as it is implemented with a digital state machine instead of a microcontroller.
- How does the TUSB2077A handle overcurrent conditions?
The TUSB2077A can detect overcurrent conditions on a per-port or ganged basis. In the event of an overcurrent, it can switch off power to the affected port(s) accordingly.
- Can the TUSB2077A support custom vendor and product IDs?
- What is the purpose of the EXTMEM pin on the TUSB2077A?
The EXTMEM pin enables or disables the optional EEPROM interface. When high, it disables the EEPROM interface and uses default vendor and product IDs.
- How does the TUSB2077A support suspend and resume operations?
The TUSB2077A supports suspend and resume operations with a suspend status pin available for external logic power down.
- What kind of thermal management does the TUSB2077A require?
The TUSB2077A has specific thermal resistance values, such as junction-to-ambient and junction-to-case, which need to be considered for proper thermal management.
